#include<stdio.h>
#include<stdlib.h>

const char* filename="pass";

int main(){
  FILE* pf=fopen(filename,"a");
  FILE* pf1=fopen("hello","r");
  char contain[12];
  int index=0;
  char ch;
  while(( ch=fgetc(pf1))!=EOF){
    contain[index++]=ch;
    if(index==12){
      fwrite(contain,12,1,pf);
      index=0;
     }
  }
  fwrite(contain,index,1,pf);
  fclose(pf1);
  fclose(pf);
  return 0;
}
